Ol Doinyo Eburru is an active complex of

volcano A volcano is a rupture in the Crust (geology), crust of a Planet#Planetary-mass objects, planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and volcanic gas, gases to escape from a magma chamber below the surface. On Ear ...

es in the Great Rift Valley, Kenya to the northwest of

Lake Naivasha Lake Naivasha is a freshwater lake in Kenya, outside the town of Naivasha in Nakuru County, which lies north west of Nairobi. It is part of the Great Rift Valley. The name derives from the local Maasai name ''Nai'posha'', meaning "rough wate ...

. It is being exploited for geothermal energy. Soysambu Conservancy is located to the north of the massif, between Lake Elmenteita to the east and

Lake Nakuru Lake Nakuru is one of the Rift Valley lakes at an elevation of above sea level. It lies to the south of Nakuru, in the rift valley of Kenya and is protected by Lake Nakuru National Park. The lake's abundance of algae used to attract a vast qu ...

to the west.

Geology

Eburru is part of a group of volcanoes in the rift that also includes

Suswa Suswa is a small town along the main road from Nairobi to Narok town and at the foot of Mount Suswa in Narok County. Suswa is also a ward in Narok East sub-county. The Suswa sub-station is located just outside town and electricity that is generat ...

, Longonot,

Olkaria The Olkaria Area is a region located immediately to the south of Lake Naivasha in the Great Rift Valley of Kenya, Africa. It is geothermally active and is being used to generate clean electric power. The region has an estimated potential of 2,000 ...

, Elmenteita and

Menengai Menengai Crater is a massive shield volcano with one of the biggest calderas in the world, in the Great Rift Valley, Kenya. It is the largest volcano caldera in Kenya and the second largest volcano caldera in Africa. Volcanic formed rich loam so ...

. It is separated from Olkaria volcano to the south by the Akira plains. In this part of the rift, the eastern margin is covered by

trachytic Trachyte () is an extrusive igneous rock composed mostly of alkali feldspar. It is usually light-colored and aphanitic (fine-grained), with minor amounts of mafic minerals, and is formed by the rapid cooling of lava enriched with silica and ...

tuff Tuff is a type of rock made of volcanic ash ejected from a vent during a volcanic eruption. Following ejection and deposition, the ash is lithified into a solid rock. Rock that contains greater than 75% ash is considered tuff, while rock ...

s, often ignimbritic, and some trachytic

lava Lava is molten or partially molten rock (magma) that has been expelled from the interior of a terrestrial planet (such as Earth) or a moon onto its surface. Lava may be erupted at a volcano or through a fracture in the crust, on land or un ...

s. The western margin is covered by trachytic and pantelleritic

pumice Pumice (), called pumicite in its powdered or dust form, is a volcanic rock that consists of highly vesicular rough-textured volcanic glass, which may or may not contain crystals. It is typically light-colored. Scoria is another vesicular v ...

as well as deposits of

ash Ash or ashes are the solid remnants of fires. Specifically, ''ash'' refers to all non-aqueous, non- gaseous residues that remain after something burns. In analytical chemistry, to analyse the mineral and metal content of chemical samples, ash ...

falls ejected from Eburru. Ol Doinyo Eburru

The Eburru massif rises to above the floor of the rift. It developed in three stages. The products of the first stage, in the west, are now mostly buried apart from small pantelleritic lava outcrops. The second stage formed the Waterloo Ridge on the eastern side of the massif. These rocks came from a series of pyroclastic eruptions originating in a fault zone. The third stage created craters, small cones, domes and lava flows. The summit has more than fifty craters with diameters from to . The pumice lapilli and ash beds from these centers covers most of the massif as well as the western shoulder of the rift. The youngest formations are no more than a few hundred years old. The Eburru massif today is ridge-shaped and eroded, with an east–west orientation. The volcanic complex has an area of . There are two summits, Eburru hill and West hill. There are young craters on the eastern part of the ridge. The east flank has

rhyolitic Rhyolite ( ) is the most silica-rich of volcanic rocks. It is generally glassy or fine-grained (aphanitic) in texture, but may be porphyritic, containing larger mineral crystals (phenocrysts) in an otherwise fine-grained groundmass. The mineral ...

domes that were probably created in the

Holocene The Holocene ( ) is the current geological epoch. It began approximately 11,650 cal years Before Present (), after the Last Glacial Period, which concluded with the Holocene glacial retreat. The Holocene and the preceding Pleistocene togeth ...

and are still only partly overgrown with vegetation. There are widespread

fumarole A fumarole (or fumerole) is a vent in the surface of the Earth or other rocky planet from which hot volcanic gases and vapors are emitted, without any accompanying liquids or solids. Fumaroles are characteristic of the late stages of volcani ...

s in cinder cones and craters along the faults in the massif.

Geothermal development

In October 2009 Geothermal Development Associates announced that they had signed a contract with Kenya Electricity Generating Company Limited to design, supply and commission a wellhead geothermal power plant at Eburru. The plant would include a 2.5 MW steam turbine generator manufactured by Elliott Turbomachinery in

Jeannette, Pennsylvania Jeannette is a city in Westmoreland County, Pennsylvania, United States. Jeannette was founded in 1888. The city got its name from one of the original city fathers, who wished to honor his wife, Jeannette McLaughlin, by giving the new town her fi ...

. It has been estimated that Eburru could support a 20 MW geothermal power station.

References

Sources

* * * * * {{Great Rift Valley, Kenya Volcanoes of Kenya Mountains of Kenya Great Rift Valley Landforms of Rift Valley Province Nakuru County Active volcanoes Quaternary Africa Complex volcanoes